A 64-bit processor is a CPU that handles data in chunks of 64 bits at a time, using internal storage slots (called registers) that are 64 bits wide. In practical terms, this means the processor can work with larger numbers, access far more memory, and move twice as much data per clock cycle compared to older 32-bit designs. Every modern computer, phone, and tablet sold today runs on a 64-bit processor.
What “64-Bit” Actually Means
The “bits” in a processor’s name describe the width of its registers, which are tiny, ultra-fast storage locations inside the chip itself. When a processor performs a calculation or moves data around, it loads values into these registers first. A 64-bit register can hold a number as large as about 18.4 quintillion (2 to the 64th power), while a 32-bit register tops out at roughly 4.3 billion.
This wider data path also extends to the buses that connect the processor to the rest of the system. With a 64-bit data bus, the chip carries twice the payload per clock cycle that a 32-bit chip could. Think of it like widening a highway from four lanes to eight: more data gets through in the same amount of time.
The Memory Advantage
The most tangible benefit for everyday users is memory. A 32-bit processor can address a maximum of 4 GB of RAM, a hard ceiling that became a real bottleneck as software grew more demanding. A 64-bit processor can theoretically address up to 16 exabytes of RAM, which is 16 billion gigabytes.
No computer actually uses that much. Current chips don’t wire up all 64 address lines because there’s no need yet. Most desktop and laptop processors today support a 48-bit physical address space, which allows for 256 terabytes of RAM. A few higher-end server chips extend this to 52 or 57 bits. The 64-bit architecture simply gives hardware designers room to grow for decades without needing a new standard.
Where 64-Bit Processing Makes a Difference
Not every task benefits equally from a 64-bit processor. The biggest gains show up in work that involves large data sets or heavy number-crunching: video encoding, scientific simulations, encryption, and large databases all run significantly faster when they can use wide registers and access large pools of memory. A video editor rendering 4K footage, for example, needs to hold enormous frames in memory and perform millions of calculations per second on them.
For lighter tasks like web browsing, word processing, or even some 3D games, the jump from 32-bit to 64-bit hardware alone doesn’t produce a dramatic speed increase. The real-world benefit there comes indirectly: your operating system and background processes can use more memory, so the whole system stays responsive even when you have dozens of browser tabs and apps open simultaneously.
How 64-Bit Processors Run Older Software
When 64-bit processors first arrived in consumer PCs, billions of existing programs were still 32-bit. To avoid breaking everything, chip makers built backward compatibility directly into the hardware. A 64-bit processor can switch its operating mode to execute 32-bit instructions natively, with no special hardware layer required.
On Windows, a subsystem called WOW64 manages this process. It creates a 32-bit environment within the 64-bit operating system, letting older programs run without modification. The processor handles the mode-switching automatically, so users rarely notice any difference. macOS and Linux have similar compatibility layers, though Apple eventually dropped 32-bit app support entirely starting with macOS Catalina in 2019.
64-Bit on Phones and Tablets
The mobile world followed a similar path. ARM, the company whose chip designs power virtually all smartphones, announced its 64-bit architecture (called ARMv8-A) in 2011. Apple was the first to ship a 64-bit mobile chip with the iPhone 5s in 2013.
Android caught up quickly. The last Android version that supported only 32-bit processors was KitKat, released in 2013. Starting with Lollipop in 2014, Android could run both 32-bit and 64-bit apps. Google began requiring developers to include 64-bit versions of their apps on the Play Store in August 2019, though 32-bit apps continued to be supported on devices that could run them. Today, virtually every new phone ships with a 64-bit processor, and both iOS and Android have been steadily phasing out 32-bit app support.
How to Tell If Your System Is 64-Bit
On Windows, open Settings, then System, then About. Look for “System type,” which will say either “64-bit operating system, x64-based processor” or a 32-bit equivalent. On a Mac, every Mac sold since 2007 has had a 64-bit processor, and every version of macOS since Catalina is 64-bit only. On Android, you can check under Settings, then About Phone, where some devices list the processor architecture. iPhones have been exclusively 64-bit since the iPhone 5s.
If you’re buying any new computer or phone in 2024 or later, it will be 64-bit. The only scenario where 32-bit still matters is maintaining very old hardware or running legacy software that was never updated.